1. Field of the Invention
The present invention relates generally to egg processing, and in particular to a method and apparatus for collecting albumen drippings on an egg processing machine.
2. Description of the Prior Art
The edible or "eggmeat" portion of an egg consists primarily of a yolk and a quantity of albumen, the latter being commonly referred to as "egg white" and surrounding the yolk in an eggshell. A large portion of the approximately 70 billion eggs produced in the United States each year is sold to consumers and the food service industry for use as whole eggs. However, there is also a vast demand for separated yolk and albumen products. For example, albumen (or ovalbumen) is used commercially in the leather industry, in foodstuffs, as a clarifying agent, in photography, in adhesives and in sugar refining. Since albumen has a much lower cholesterol content than egg yolk, it is often preferred as a food or a food ingredient by persons wishing to limit their cholesterol intake. Egg yolks are commonly used in baking, dairy products, mayonnaise, pharmaceuticals, soap and perfumery.
Egg processing machines have heretofore been proposed which automatically break the eggs, separate the albumen and yolk and collect the eggmeat products for distribution and resale. For example, the inventor's U.S. Pat. No. 2,900,071 discloses a mechanism for separating egg whites from egg yolks wherein multiple receptacles are mounted on an endless chain of a conveyor. The receptacles receive, separate and dump the egg contents at appropriate locations along the path of conveyor travel.
A machine for automatically receiving, retaining and breaking eggs is shown in the inventor's U.S. Pat. No. 2,792,040 and includes a rotary head or turret for holding successive eggs at a cracking station. The eggmeat contents are delivered from the breaking machine to conveyor-mounted separating devices.
An undesirable characteristic of albumen, at least for processing purposes, is that it is highly viscous and tends to cling to the eggshells and egg yolks. Egg processing tends to be highly competitive and relatively small improvements in efficiency can result in substantial profit gains. Hence, it is highly desirable to recover as much albumen as possible from each processed egg. To this end, prior art devices have been proposed for extracting the small amounts of albumen that cling to the broken eggshells after the yolk and most of the albumen are removed therefrom.
For example, the Laffler U.S. Pat. No. 1,945,860 discloses nozzles over which the eggshell halves are placed for receiving blasts of compressed air whereby the albumen is forced from the eggshell halves. Eggshell halves are also placed over nozzles in the apparatus disclosed in the Irish U.S. Pat. No. 2,206,959, wherein suction is used to extract the albumen for collection in a container which is connected to a vacuum pump.
Yet another solution to this problem is proposed in the inventor's U.S. Pat. No. 3,854,394 for an egg liquid extractor apparatus. The apparatus disclosed therein includes conveyor belts for crushing egg material therebetween. The liquid albumen squeezed from the egg material, which can include whole eggs, is separated from the larger pieces of eggshell, but it is generally not considered suitable for human consumption because of the presence of smaller eggshell fragments and the use of whole eggs which, for various reasons, have been deemed inedible by humans.
Some automatic egg processing machines rely on gravity to discharge and separate the eggmeat. In such machines, the eggshells are broken, the halves separated and the contents dumped into a yolk cup with a notch or opening which permits the albumen to overflow into an albumen cup. Because of the highly viscous nature of the albumen, the invariable drippings (often referred to as "stringers" in the industry) remain suspended from the eggshell halves and are usually discarded therewith. Hence, a certain amount of edible albumen is wasted with such prior art machines. Such a reliance on gravity is detrimental because modern egg processing machines process several hundred eggs per minute and allow relatively little time for albumen stringers to be collected by gravity. Furthermore, albumen is more viscous at lower temperatures and if the egg processing plant is unheated or the input eggs are relatively cold, gravity flow is impeded.
Heretofore there has not been available an albumen collection apparatus and method with the advantages and features of the present invention.